Computing resource service providers and other service providers often maintain and operating various physical hosts to support various computing resources, including virtual machines, on behalf of their customers. These physical hosts may be part of a diverse heterogeneous fleet of physical hosts that are built using various characteristic axes. However, as new axes are introduced into the fleet, new comparisons may need to be performed in order to identify any compatible physical hosts within the fleet. This may result in additional expense and use of available resources, as these comparisons may need to be updated regularly with every introduction of a new characteristic axis for the fleet of physical hosts.